Selective herbicidal composition

ABSTRACT

A selective herbicidal composition for controlling grasses and weeds in crops of cultivated plants comprising, in addition to customary formulation assistants, 
     a) a herbicide selected from the group consisting of sulfonyl ureas, sulfonamides and imidazolinones; and 
     b) a water-soluble iron compound.

This is a continuation-in-part application of International applicationPCT/EP 96/02857 filed Jun. 29, 1996.

The present invention relates to a novel selective herbicidalcomposition for controlling grasses and weeds in crops of cultivatedplants, which composition comprises a herbicide and an iron compound andprotects the cultivated plants, but not the weeds, from the phytotoxicaction of the herbicide, and to the use of said composition forcontrolling weeds in crops of cultivated plants.

When applying herbicides, the cultivated plants may also suffer severedamage owing to factors that include the concentration of the herbicideand the mode of application, the cultivated plant itself, the nature ofthe soil, and the climatic conditions such as exposure to light,temperature and rainfall.

To counteract this problem and similar ones, the proposal has alreadybeen made to use different compounds e.g. as antidote or safener whichare able to antagonise the harmful action of the herbicide on thecultivated plant, i.e. to protect the cultivated plant while leaving theherbicidal action on the weeds to be controlled virtually unimpaired. Ithas, however, been found that the proposed compounds often have a veryspecific action, not only with respect to the cultivated plants but alsoto the herbicide, and in some cases also subject to the mode ofapplication.

Surprisingly, it has now been found that a variable amount of acombination of herbicidal acetolactate synthase inhibitors (ALSinhibitors) with specific iron compounds develops an increasedselectivity of the respective ALS inhibitors for the crops of cultivatedplants, which combination is able to control the majority of weeds thatoccur preferably in crops of cultivated plants by the preemergence aswell as, in particular, by the postemergence method withoutsubstantially damaging the cultivated plant.

Accordingly, the invention proposes a selective herbicidal compositioncomprising, in addition to customary inert formulation assistants suchas carriers, solvents and wetting agents, a mixture of

a) a herbicidally effective acetolactate synthase inhibitor (ALSinhibitor) selected from the group consisting of sulfonyl ureas,sulfonamides and imidazolinones; and

b) a water-soluble iron compound.

In the compositions of this invention it is preferred to use

a) the herbicidally effective acetolactate synthase inhibitors of thesulfonyl urea group which are characterised in that they correspond toformula A

wherein

E is a group of formula

W is a group of formula

R and R₁ are each independently of the other hydrogen, methyl ormethoxy;

R₂ is chloro, nitro, —CH₂CH₂CF₃, —OCH₂CH₂OCH₃, —OCH₂CH₂Cl, —COO—C₁alkyl,

—COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl;

R₄ is —COOCH₃, —CF₃, —OCHF₂, —OCH₂CF₃, —OCH₂CHCIF, —CON(CH₃)₂ or—SO₂C₂H₅;

R₀₄ is hydrogen or —CF₃;

R₅ is —COO—C₁alkyl or —COO—C₂alkyl or the group of formula

R₆ is hydrogen or chloro;

R₇ is methyl or the group of formula

R₈ is chloro or —SO₂C₂H₅;

X₁ is chloro, methyl, methoxy or —OCHF₂;

Y₁ is methyl, methoxy or —OCHF₂;

X₂ is methyl, methoxy, ethoxy, —CF₃ or —N(CH₃)₂; and

Y₂ is —CF₃, methoxy, —OCH₂CF₃ or —NHCH₃, and the salts of thosecompounds;

those herbicidally effective acetolactate synthase inhibitors of thesulfonamide group which are characterised in that they correspond toformula C

wherein

R₁₀ is fluoro or chloro;

R₁₁ is fluoro, chloro or a —COOCH₃ group;

R₁₂ is hydrogen or methyl;

R₁₃ is hydrogen or fluoro;

R₁₄ is hydrogen or methoxy;

V is nitrogen or a C—OC₂H₅ group; and

Q is nitrogen or a C—CH₃ or C—OCH₃ group; or

to formula C₁

wherein

R₂₂ is C₁-C₁₀alkyl, C₁-C₁₀alkyl which is substituted by halogen,C₃-C₈cycloalkyl, cyano or oxiranyl, C₂-C₈alkenyl, C₂-C₈haloalkenyl oramino; and

those herbicidally effective acetolactate synthase inhibitors of theimidazolinone group which are characterised in that they correspond toformula D

wherein

R₂₀ is hydrogen, methyl, ethyl or a —CH₂—OCH₃ group;

R₂₁ is hydrogen; or

R₂₀ and R₂₁, taken together, form a —CH═CH—CH═CH— group; and

b) water-soluble iron compounds which are characterised in that theycorrespond to formula B

[Fe^(II,III)-Z]  (B),

wherein

Fe^(II,III) is the element iron having the oxidation number +2 (II) or+3 (III); and

Z is a mono- or polyvalent anion of inorganic or organic acids H-Z.

Compounds of formula A which are preferably used in the composition ofthis invention are those, wherein E is a group of formula

W is a group of formula

R and R₁ are each independently of the other hydrogen or methyl;

R₂ is chloro, nitro, —CH₂CH₂CF₃, —OCH₂CH₂OCH₃, —OCH₂CH₂Cl, —COO—C₁alkyl,—COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl;

R₄ is —CF₃, —OCHF₂, —OCH₂CF₃, —OCH₂CHCIF, —CON(CH₃)₂or —SO₂C₂H₅;

R₅ is —COO—C₁alkyl or —COO—C₂alkyl or the group of formula

R₆ is hydrogen or chloro;

R₇ is methyl or the group of formula

X₁ is chloro, methyl, methoxy or —OCHF₂;

Y₁ is methyl, methoxy or —OCHF₂;

X₂ is methyl, methoxy, ethoxy or —N(CH₃)₂; and

Y₂ is —CF₃, methoxy, —OCH₂CF₃ or —NHCH₃, and the salts of thosecompounds.

The sulfonyl urea compounds of formula A used according to thisinvention are known, inter alia, from “The Pesticide Manual”, TenthEdition, 1994, Editor C. Tomlin, pages 34, 85, 180, 211, 701, 734, 829,865, 904, 931, 976, 1005 and 1010; EP-A-0 084 020, EP-A-0 318 602 andEP-A-0 388 873, and some are commercially available (see Tables 1 and2).

The invention also includes the salts that the compounds of formula Acan form with in principle any bases that are capable of abstracting anacid hydrogen atom, e.g. in the —SO₂—NH—CO— grouping. Amines, hydrides,hydroxides, alcoholates, hydrogen carbonates and carbonates of alkalimetal and alkaline earth metals, especially of sodium, potassium,magnesium and calcium, have proved especially advantageous in thatconnection.

The sulfonamides of formula C and C₁ used according to this inventionand their preparation are known, inter alia, from “The PesticideManual”, Tenth Edition, 1994, Editor C. Tomlin, pages 486 and 696, andfrom EP-A-0 592 680, and some are commercially available (see Tables 5and 6).

The imidazolinones of formula D and their preparation are known, interalia, from “The Pesticide Manual”, Tenth Edition, 1994, Editor C.Tomlin, pages 584, 586 and 587, and some are commercially available (seeTable 7).

The water-soluble iron compounds of formula B are iron salts or ironchelates, wherein the iron may have the oxidation number +2 (II:divalent iron) or +3 (III: trivalent iron). The appertaining anions Zcan carry one or more than one negative charge. They can be formed fromthe corresponding inorganic or organic acids H-Z by abstracting the acidhydrogen atom. Suitable are, for example, mineral acids, such ashydrochloric acid, sulfuric acid or nitric acid, organic acids,preferably polyacids, such as (HOOC—CH₂—)₂ and

and, particularly preferably, organic acids, the iron chelates(Fe^(II,III)-Z) of which are distinguished by high stability even atbasic pH (pH values>7), typically ethylenediamine tetracetic acid(HOOC—CH₂)₂NCH₂CH₂N(CH₂—COOH)₂ (ETA),N,N′-ethylenebis[2-(2-hydroxyphenyl)glycine]

(EDDHA), diethylenetriaminepentacetic acid(HOOC—CH₂)₂NCH₂CH₂N(CH₂—COOH)CH₂CH₂N(CH₂—COOH)₂ (DTPA) andN-(2-hydroxyethyl)ethylenediaminetriacetic acidHO—CH₂CH₂N(CH₂—COOH)CH₂CH₂N(CH₂—COOH)₂ (HEDTA).

The iron chelates of formula B are obtained from iron salts and mono- orpolyvalent acids HZ, such as are also used in the preparation ofcommercial iron chelates. The preparation of such iron chelates andtheir use as micronutrients in agriculture is disclosed, inter alia, inUS-A-2 921 847.

Commercial forms of the above-mentioned iron chelates (Fe^(II,III)-Z)react according to the nature of Z acidically in aqueous solutions oremulsions, e.g. in accordance with [Fe^(II,III)-Z(—COOH)_(m)], orneutrally, e.g. in accordance with [Fe^(II,III)-Z] or[Fe^(II,III)-Z(—COO^(⊖)Me^(n⊕))_(m)], wherein m is 1, 2, 3, 4 or 5 andMe^(n⊕) is the cation of a monovalent (n=1) or polyvalent (n=2, 3, 4, or5) organic or, preferably, inorganic base, typically

Fe^(3⊕)Na^(⊕)=Fe-EDDHA (Sequestrene 138).

The invention also relates to a method of selectively controlling weedsin crops of cultivated plants, which comprises treating said cultivatedplants, the seeds or seedlings or the crop area thereof, concurrently orseparately, with a herbicidally effective amount of an ALS inhibitorselected from the group consisting of sulfonyl ureas, sulfonamides andimidazolinones, and a water-soluble iron compound.

Particularly preferred compounds of formula A are those, wherein R₂ is—COO—C₁alkyl, —COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl; X₁ is chloro or methyl; Y₁ is methylor methoxy; X₂ is methyl; and Y₂ is methoxy.

Preferred compounds of formula A for use in the composition of thisinvention are those, wherein E is a group of formula

W is a group of formula

R is hydrogen; and R₁, R₂, R₃, X₁, X₂, Y₁ and Y₂ are as defined forformula A.

Among these compounds of formula A those are particularly preferred,wherein E is a group of formula

W is a group of formula

and X₁ and Y₁ are methyl.

Preferred compounds of formula B for use in the composition of thisinvention are characterised in that group Z is an anion of EDTA, EDDHA,DTPA or HEDTA.

Among these compounds of formula B those are particularly preferred,wherein Z is an anion of EDDHA or DTPA.

Suitable compositions according to this invention are distinguished inthat they comprise a compound of formula A, wherein E is a group offormula

W is a group of formula

R₂ is —COO—C₁alkyl —COO—C₂alkyl or

is —COO—C₁alkyl or —COO—C₂alkyl; X₁ is chloro or methyl; Y₁ is methyl ormethoxy; X₂ is methyl; and Y₂ is methoxy; and a compound of formula B,wherein Z is an anion of EDTA, EDDHA, DTPA or HEDTA.

Among these compositions those are particularly suitable, wherein, inthe compounds of formula B, group Z is an anion of EDDHA or DTPA.

Particularly suitable compositions are also those, wherein, in thecompounds of formula I, substituent E is a group of formula

substituent W is a group of formula

and X₁ and Y₁ are methyl, and group Z in the compound of formula B is ananion of EDDHA or DTPA.

Particularly suitable compositions are also those, wherein, in thecompounds of formula A, substituent E is a group of formula

substituent W is a group of formula

and X₁ and Y₁ are methyl, and group Z in the compound of formula B is ananion of EDDHA or DTPA.

Among these compositions those are very particularly suitable, wherein Rand R₁ are hydrogen; and group Z in the compound of formula B is ananion of EDDHA.

Suitable cultivated plants which can be protected by the water-solubleiron compounds against the harmful action of the aforementionedherbicides are sugar beet, cereal, maize, rice, cotton wool and,preferably, soybean.

The weeds to be controlled can be monocot as well as dicot weeds.

Crop areas will be understood as meaning the areas already undercultivation with the cultivated plants or seeds thereof, as well as theareas intended for cropping with said cultivated plants.

Depending on the end use, the water-soluble iron compound can beincorporated in the soil before or after sowing. It can, however, alsobe applied by itself or together with the herbicide, preferablypostemergence. Treatment of the plants with the iron compound cantherefore in principle be carried out irrespective of the time ofapplication of the herbicide. Treatment can, however, also be carriedout by simultaneous application of the herbicide and the iron compound(e.g. as tank mixture). Preemergence treatment includes treatment of thecropping area before sowing as well as treatment of the cropping areasafter sowing but before the plants have started to grow.

The concentration of iron compound with respect to the herbicide willdepend substantially on the mode of application. Where a field treatmentis carried out either by using a tank mixture with a combination of ironcompound and herbicide or by separate application of iron compound andherbicide, the ratio of herbicide to iron compound will usually be from1:100 to 100:1, preferably from 1:20 to 20:1 and, most preferably. from1:5 to 5:1.

In field treatment it is usual to apply 0.001 to 5.0 kg/ha, preferably0.001 to 1.0 kg/ha of iron compound.

The concentration of herbicide is usually in the range from 0.001 to 0.5kg/ha, but will preferably be from 0.005 t o 0.2 kg/ha.

The compositions of this invention are suitable for all methods ofapplication commonly used in agriculture, including preemergenceapplication and, preferably, postemergence application.

For application, it is preferred to process the iron compounds orcombinations of these iron compounds with the herbicides of formulae A,C, C₁ and D, convenienty together with the customary assistants offormulation technology, typically to emulsifiable concentrates, coatablepastes, directly sprayable or dilutable solutions, dilute emulsions,wettable powders, soluble powders, dusts, granulates or microcapsules.The formulations are prepared in known manner, conveniently byhomogeneously mixing and/or grinding the active ingredients with liquidor solid formulation assistants, typically solvents or solid carriers.Surface-active compounds (surfactants) may additionally be used forpreparing the formulations.

Suitable solvents may typically be: aromatic hydrocarbons, preferablythe fractions containing 8 to 12 carbon atoms such as xylene mixtures orsubstituted naphthalenes; phthalates such as dibutyl or dioctylphthalate; aliphatic hydrocarbons such as cyclohexane or paraffins;alcohols and glycols and their ethers and esters such as ethanol,diethylene glycol, 2-methoxneth anol or 2-ethoxyethanol; ketones such ascyclohexanone; strongly polar solvents such as N-methyl-2-pyrrolidone,dimethyl sulfoxide or dimethyl formamide; as well as vegetable oils orepoxidised vegetable oils such as epoxidised coconut oil or soy beanoil; or water.

The solid carriers typically used for dusts and dispersible powders areusually natural mineral fillers such as calcite, talcum, kaolin,montmorillonite or attapulgite. To improve the physical properties it isalso possible to add highly dispersed silicic acid or highly dispersedabsorbent polymers. Suitable granulated adsorptive carriers are poroustypes, including pumice, broken brick, sepiolite or bentonite; andsuitable nonsorbent carriers are materials such as calcite or sand. Inaddition, innumerable pregranulated materials of inorganic or organicorigin may be used, especially dolomite or pulverised plant residues.

Depending on the iron compounds and, where appropriate, also on theherbicide, suitable surfactants are nonionic, cationic and/or anionicsurfactants having good emulsifying, dispersing and wetting properties.Tensides will also be understood to include surfactant mixtures.

Suitable anionic surfactants may be so-called water-soluble soaps aswell as water-soluble synthetic surface-active compounds.

Suitable soaps are the alkali metal salts, alkaline earth metal salts,ammonium salts or substituted ammonium salts of higher fatty acids(C₁₀-C₂₂), e.g. the sodium or potassium salts of oleic or stearic acid,or of natural fatty acid mixtures which can be obtained, inter alia,from coconut oil or tallow oil. Further suitable soaps are also thefatty acid methyl taurin salts.

More often, however, so-called synthetic surfactants are used,especially fatty alcohol sulfonates, fatty alcohol sulfates, sulfonatedbenzimidazole derivatives or alk ylaryl sulfonates.

The fatty alcohol sulfonates or sulfates are usually in the form ofalkali metal salts, alkaline earth metal salts, ammonium salts orsubstituted ammonium salts, and they contain a C₈-C₂₂alkyl radical whichalso includes the alkyl moiety of acyl radicals, e.g. the sodium orcalcium salt of liyninsulfonic acid, of dodecylsulfate, or of a mixtureof fatty alcohol sulfates obtained from natural fatty acids. Thesecompounds also comprise the salts of sulfated and sulfonated fattyalcohol/ethylene oxide adducts. The sulfonated benzimidazole derivativespreferably contain two sulfonic acid groups and one fatty acid radicalcontaining 8 to 22 carbon atoms. Illustrative examples of alkylarylsulfonates are the sodium, calcium or triethanolamine salts ofdodecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, or of acondensate of naphthalenesulfonic acid and formaldehyde.

Corresponding phosphates, typically salts of the phosphoric acid esterof an adduct of p-nonylphenol with 4 to 14 ethylene oxide orphospholipids, are also suitable.

Nonionic surfactants are preferably polyglycol ether derivatives ofaliphatic or cycloaliphatic alcohols or of saturated or unsaturatedfatty acids and alkylphenols, said derivatives containing 3 to 30 glycolether groups and 8 to 20 carbon atoms in the (aliphatic) hydrocarbonmoiety and 6 to 18 carbon atoms in the alkyl moiety of the alkylphenols.

Further suitable nonionic surfactants are the water-soluble polyadductsof polyethylene oxide with polypropylene glycol,ethylenediaminopolypropylene glycol and alkylpolypropylene glycolcontaining 1 to 10 carbon atoms in the alkyl chain, which polyadductscontain 20 to 250 ethylene glycol ether groups and 10 to 100 propyleneglycol ether groups. These compounds usually contain 1 to 5 ethyleneglycol units per propylene glycol unit.

Illustrative examples of nonionic surfactants are nonylphenolpolyethoxyethanols, castor oil polyglycol ether, polyadducts ofpolypropylene and polyethylene oxide, tributylphenoxy polyethoxyethanol,polyethylene glycol and octylphenoxy polyethoxyethanol.

Fatty acid esters of polyoxyethylene sorbitan are also suitable nonionicsurfactants, typically polyoxyethylene sorbitan trioleate.

Cationic surfactants are preferably quaternary ammonium salts carrying,as N-substituent, at least one C₈-C₂₂alkyl radical and, as furthersubstituents, unsubstituted or halogenated lower alkyl, benzyl orhydroxy-lower alkyl radicals. The salts are preferably in the form ofhalides, methyl sulfates or ethyl sulfates, for example stearyltrimethylammonium chloride or benzyl bis(2-chloroethyl)ethylammoniumbromide.

The surfactants customarily employed in the art of formulation and whichcan also be used in the compositions of this invention are described,inter alia, in “Mc Cutcheon's Detergents and Emulsifiers Annual” MCPublishing Corp., Ridgewood N.J., 1981, Stache, H.,“Tensid-Taschenbuch”, Carl Hanser Verlag, Miinchen/Wien, 1981 and M. andJ. Ash, “Encyclopedia of Surfactants”, Vol I-III, Chemical PublishingCo., New York, 1980-81.

The agrochemical formulations will usually contain from 0.1 to 99% byweight, preferably from 0.1 to 95% by weight, of iron compound or of acompound mixture of iron compound and herbicide, from 1 to 99.9% byweight, preferably from 5 to 99.8% by weight of a solid or liquidformulation assistant, and from 0 to 25% by weight, preferably from 0.1to 25% by weight, of a surfactant.

Whereas it is preferred to formulate commercial products asconcentrates, the end user will normally use dilute formulations.

The compositions may also contain further adjuvants such as stabilisers,antifoams, viscosity regulators, binders, tackifiers or other activeingredients, e.g. additional sulfonyl ureas and further herbicidalacetolacetate synthase inhibitors (ALS inhibitors), typically additionalsufonamides and imidazolinones as well as further metal chelates of, forexample, calcium, magnesium, zinc or manganese and also further traceelements which are import ant for the physiology of the plant.

Different methods and techniques may suitably be used for applying thewater-soluble iron compounds or compositions containing them forselectively protecting cultivated plants from the harmful effects ofacetolacetate synthase inhibitors, for example the following:

i) Application as a tank mixture

A liquid formulation of a mixture of iron compound and herbicide(reciprocal ratio from 10:1 to 1:100) is used, the concentration ofherbicide being from 0.001 to 0.2 kg/ha. This tank mixture is appliedbefore or after sowing.

ii) Application in the furrow

The iron compound formulated as emulsifiable concentrate, wettablepowder or granulate is applied to the open furrow in which t he seedshave been sown. After covering the furrow, the herbicide is appliedpreemergence in conventional manner.

iii) Controlled release of safener

A solution of the compound of formula B is applied to mineral granulatesubstrates or polymerised granulates (urea/formaldehyde) and allowed todry. A coating may additionally be applied (coated granulates) whichpermits controlled release of the safener over a specific period oftime.

The invention is illustrated in more detail by the followingnon-limitative Examples.

Formulation Examples for mixtures of sulfonyl urea herbicides of formulaA, sulfonamide herbicides of formula C and C₁, imidazolinone herbicidesof formula D and iron compounds of formula B used according to thisinvention (throughout, percentages are by weight)

F1. Emulsifiable concentrates a) b) c) d) compound mixture  5% 10% 25%50% calcium dodecylbenzenesulfonate  6%  8%  6%  8% polyethoxylatedcastor oil  4% —  4%  4% (36 mol EO) octylphenol polyethoxylate —  4% — 2% (7-8 mol EO) cyclohexanone — — 10% 20% mixture of aromatichydrocarbons 85% 78% 55% 16% C₉—C₁₂

Emulsions of any desired concentration can be prepared by diluting suchconcentrates with water.

F2. Solutions a) b) c) d) compound mixture  5% 10% 50% 90% dipropyleneglycol methyl ether — 20% 20% — polyethylene glycol 400 20% 10% — —N-methyl-2-pyrrolidone — — 30% 10% mixture of aromatic hydrocarbons 75%60% — — C₉—C₁₂

The solutions are suitable for use as microdrops.

F3. Wettable powders a) b) c) d) compound mixture  5% 25% 50% 80% sodiumligninsulfonate  4% —  3% — sodium laurylsulfate  2%  3% —  4% sodiumdiisobutylnaphthalene sulfonate —  6%  5%  6% octylphenol polyethoxylate—  1%  2% — (7-8 mol EO) highly dispersed silica  1%  3%  5% 10% kaolin88% 62% 35% —

The compound mixture is throughly mixed with the adjuvants and thismixture is ground in a suitable mill to give wettable powders which canbe diluted with water to give suspensions of any desired concentration.

F4. Coated granulates a) b) c) compound mixture  0.1%  5% 15% highlydispersed silica  0.9%  2%  2% inorganic carrier 99.0% 93% 83% (Ø 0.1-1mm) e.g. CaCO₃ or SiO₂

The compound mixture is dissolved in methylene chloride, the solution issprayed on to the carrier, and the solvent is removed under vacuum.

F5. Coated granulates a) b) c) compound mixture  0.1%  5% 15%polyethylene glycol 200  1.0%  2%  3% highly dispersed silica  0.9%  1% 2% inorganic carrier 98.0% 92% 80% (Ø 0.1-1 mm) e.g. CaCO₃ or SiO₂

The finely ground compound mixture is uniformly applied in a mixer tothe carrier substrate moistened with polyethylene glycol. Non-dustycoated granulates are obtained in this manner.

F6. Extruder granulates a) b) c) d) compound mixture  0.1%  3%  5% 15%sodium ligninsulfonate  1.5%  2%  3%  4% carboxymethyl cellulose  1.4% 2%  2%  2% kaolin 97.0% 93% 90% 79%

The compound mixture is mixed with the adjuvants and the mixture ismoistened with water. This mixture is extruded and then dried in astream of air.

F7. Dusts a) b) c) compound mixture  0.1%  1%  5% talcum 39.9% 49% 35%kaolin 60.0% 50% 60%

Ready for use dusts are obtained by mixing the the active ingredientwith the carriers on a suitable mill.

F8. Suspension concentrates a) b) c) d) compound mixture   3%  10%  25% 50% ethylene glycol   5%   5%   5%   5% nonylphenol polyethoxylate —  1%   2% — (15 mol EO) sodium ligninsulfonate   3%   3%   4%   5%carboxymethyl cellulose   1%   1%   1%   1% 37% aqueous formaldehyde0.2% 0.2% 0.2% 0.2% solution silicone oil emulsion 0.8% 0.8% 0.8% 0.8%water  87%  79%  62%  38%

The finely ground compound mixture is intimately mixed with theadjuvants to give a suspension concentrate from which suspensions of anydesired concentration can be prepared by dilution with water.

Illustrative examples of particularly suitable compounds of formula Aare given in Tables 1 and 2 below.

TABLE 1 Herbicides of formula A (A)

Cmpd Common name or No. E R₁ R₂ R W X_(1 or 2) Y_(1 or 2) reference lit.1.1 E₁ H Cl H W₂ CH₃ OCH₃ chlorosulfurone 1.2 E₁ H COOCH₃ CH₃ W₂ CH₃OCH₃ tribenurone 1.3 E₁ H COOCH₃ H W₂ CH₃ OCH₃ metsulfurone 1.4 E₁ HOCH₂CH₂OCH₃ H W₂ OCH₃ OCH₃ cinosulfurone 1.5 E₁ H OCH₂CH₂Cl H W₂ CH₃OCH₃ triasulfurone 1.6 E₁ H CH₂CH₂CF₃ H W₂ CH₃ OCH₃ prosulfurone 1.7 E₁H COOCH₃ H W₁ OCHF₂ OCHF₂ primisulfurone 1.8 E₁ H COOCH₃ H W₁ OCHF₂ CH₃EP-A-0 084 020 1.9 E₁ H NO₂ H W₁ OCHF₂ CH₃ EP-A-0 084 020 1.10 E₁ HCOOCH₃ H W₁ CH₃ CH₃ sulfometurone 1.11 E₁ H COOC₂H₅ H W₁ OCH₃ Clchloroimurone 1.12 E₁ H COOCH H W₂ OC₂H₅ NHCH₃ ethametsulfurone 1.13 E₁CH₃ COOCH₃ H W₂ OCH₂CF₃ N(CH₃)₂ triflusulfurone 1.14 E₁ H

H W₁ CH₃ CH₃ EP-A-0 496 701 1.15 E₁ H COOCH₃ H W₂ CF₃ OCH₃ EP-A-0 388873

TABLE 2 Herbicides of formula A

Cmpd Common name or No. E R W reference lit. 2.1

H

bensulfurone 2.2

H

cyclosulfamurone 2.3

H

nicosulfurone 2.4

H

rimsulfurone 2.5

H

fluzasulfurone 2.6

H

thiphensulfurone 2.7

H

halosulfurone 2.8

H

pyrazosulfurone (NC 311) 2.9

H

EP-A-0 318 602 (NC 330) 2.10

H

azimsulfurone 2.11

H

amidosulfurone 2.12

H

flupyrsulfurone 2.13

H

sulfosulfurone 2.14

H

2.15

Illustrative examples of particularly suitable iron compounds of formulaB are given in Table 3 below.

TABLE 3 Iron compounds of formula B [Fe^(II,III)-Z]    (B)[Fe^(II,III)-Z] (commerical forms) 3.1 FeCl₃ 3.2 FeSO₄ 3.3 Fe-EDTA 3.4Fe-EDDHA (=Sequestrene 138) 3.5 Fe-DTPA (=Sequestrene 330) 3.6 Fe-HEDTA

Illustrative examples of particularly suitable mixture combinations ofthe compounds of Tables 1 and 2 and of Table 3 are given in Table 4below.

TABLE 4 Mixture combinations of the herbicide of formula A (Tables 1 and2) and the iron compound of formula B (Table 3) Cmpd No. Herbicide AIron compound B 4.1  1.11 3.3 4.2  1.11 3.4 4.3  1.11 3.5 4.4  1.11 3.64.5  2.6  3.3 4.6  2.6  3.4 4.7  2.6  3.5 4.8  2.6  3.6 4.9  1.14 3.14.10 1.14 3.2 4.11 1.14 3.3 4.12 1.14 3.4 4.13 1.14 3.5 4.14 1.14 3.6

Illustrative examples of particularly suitable compounds of formulae C,C₁ and D are given in Tables 5, 6 and 7 below.

TABLE 5 Herbicides of formula C (C)

Common Comp No. R₁₀ R₁₁ R₁₂ R₁₃ R₁₄ V Q name or reference lit. 5.1 F F HH H N C-Me flumetsulam 5.2 Cl Cl Me H OMe N C-OMe metosulam 5.3 ClCOOCH₃ H F H C-OEt N cloransulam

TABLE 6 Herbicides of formula C₁ (C₁)

Cmpd No. R₂₂ 6.1 —CH₂—CH═CHCl (Z) 6.2 —CH₂—CH═CHCl (E) 6.3 —CH₂—CCl═CH₂6.4 —CH₂—CCl═CHCl 6.5 —CH₂—C(CH₃)═CHCl 6.6 —CH₂—CBr═CH₂ 6.7—CH₂—CCl═CHCH₃ 6.8 —CH₂—CH═CHBr 6.9 —CH₂—CHCl—CH₂Cl 6.10

6.11 —CH₂—C(CH₃)₃ 6.12

6.13 —CH₂—CH₂CN 6.14 —CH₂—CH═CClCH₃ 6.15 —CH₂—CH═C(CH₃)₂ 6.16—CH₂—CH₂—C(CH₃)₃═CH₂ 6.17 —CH₂—CH═CCl₂ 6.18 —CH═CH—CH₂CH₃ 6.19 —NH2 6.20—CH₂—CH═CHCl 6.21 —CH₂—C(CH₃)═CH₂ The compounds 6.1 to 6.21 and theirpreparation are described in EP-A-0 592 680. Compounds 6.3 to 6.21 aremixtures of (Z) and (E) isomers.

TABLE 7 Herbicides of formula D (D)

Common name or Cmpd No. R₂₀ R₂₁ reference lit. 7.1 —CH═CH—CH═CH—Imazaquin (Scepter ®) 7.2 Et H Imazethapyr (Pursuit ®) 7.3 H H Imazapyr7.4 Me H Imazamethapyr 7.5 —CH₂OMe H Imazamox (Bolero ®)

The following Examples illustrate the ability of the water-soluble ironcompounds to protect cultivated plants from the phytotoxic action of theASL inhibitors used according to this invention and selected from thegroup consisting of sulfonyl urea, sulfonamide and imidazolinoneherbicides and to increase the selectivity of the sulfonyl urea,sulfonamide and imidazolinone herbicides used according to thisinvention.

BIOLOGICAL EXAMPLES Example B1 Postemergence Herbicidal Action (ContactHerbicide)

The test plants are raised under greenhouse conditions in plastic potsto the 2-3 leaf stage. The growth substrate is standard soil. To thetest plants are applied at this stage the herbicides by themselves oralso in admixture. Application is made with an aqueous suspension of thetest substances, prepared from a 25% wettable powder formulation(Example F3, b)), in 500 l of water/ha, with a standard spray nozzle.The rates of application are governed by the optimum rates determinedaccording to field and greenhouse conditions.

The tests are evaluated after 21 days (percentage of action, 100=plantwithered, 0=no phytotoxic action).

Test plants: soybean, Amaranthus, Chenopodium.

The results obtained from this test show that by using the ironcompounds of formula B the selectivity of the herbicides of formulae A,C, C₁ and D against the cultivated plants can be markedly enhanced whilethe herbicidal activity against the weeds is retained.

Tables B1 to B8 illustrate this.

Table B1: Postemergence herbicidal action of compound No. 1.14 by itselfand in combination with in each case 1000 g/ha of Sequestrene 138; rateof application 60 g, 90 g and 120 g of active substance/ha.

Cmpd No. 1.14 Cmpd No. 1.14 [g ai/ha] [g ai/ha] +Sequestrene 138 Testplants 120 90 60 120 90 60 1000 g/ha Soybean 50 40 20 20 10 10Amaranthus 98 98 98 98 Chenopodium 98 90 98 98

Table B2: Postemergence herbicidal action of compound No. 1.14 by itselfand in combination with in each case 1000 g/ha of FeCl₂; rate ofapplication 60 g, 90 g and 120 g of active substance/ha.

Cmpd No. 1.14 Cmpd No. 1.14 [g ai/ha] [g ai/ha] +FeCl₂ Test plants 12090 60 120 90 60 1000 g/ha Soybean 50 40 20 20 10 10 Amaranthus 98 98 9898 Chenopodium 98 90 98 95

Table B3: Postemergence herbicidal action of compound No. 1.14 by itselfand in combination with in each case 1000 g/ha of Fe-EDTA; rate ofapplication 60 g, 90 g and 120 g of active substance/ha.

Cmpd No. 1.14 Cmpd No. 1.14 [g ai/ha] [g ai/ha] +Fe-EDTA Test plants 12090 60 120 90 60 1000 g/ha Soybean 50 40 20 30 30 20 Amaranthus 98 98 9898 Chenopodium 98 90 98 98

Table B4: Postemergence herbicidal action of compound No. 1.11 by itselfand in combination with in each case 1000 g/ha of Sequestrene 330; rateof application 8 g, 15 g and 30 g of active substance/ha.

Cmpd No. 1.11 Cmpd No. 1.11 [g ai/ha] [g ai/ha] +Sequestrene 330 Testplants 30 15 8 30 15 8 1000 g/ha Soybean 85 70 50 35 35 20 Amaranthus 6060 60 60 60 60 Chenopodium 30 30 30 30 20 20

Table B5: Postemergence herbicidal action of compound No. 2.6 by itselfand in combination with in each case 1000 g/ha of Sequestrene 330; rateof application 8 g, 15 g and 30 g of active substance/ha.

Cmpd No. 2.6 Cmpd No. 2.6 [g ai/ha] [g ai/ha] +Sequestrene 330 Testplants 30 15 8 30 15 8 1000 g/ha Soybean 95 90 85 80 75 50 Amaranthus 6060 60 60 60 60 Chenopodium 95 95 90 90 90 80

Table B6: Postemergence herbicidal action of compound No. 7.2 by itselfand in combination with in each case 1000 g/ha of Sequestrene 330; rateof application 70 g and 140 g of active substance/ha.

Cmpd No. 7.2 Cmpd No. 7.2 [g ai/ha] [g ai/ha] +Sequestrene 330 Testplants 140 70 140 70 1000 g/ha Soybean 70 35 35 35 Amaranthus 70 70 6050 Chenopodium 50  0 35 30

Table B7: Postemergence herbicidal action of compound No. 7.1 by itselfand in combination with in each case 1000 g/ha of Sequestrene 330; rateof application 90 g and 180 g of active substance/ha.

Cmpd No. 7.1 Cmpd No. 7.1 [g ai/ha] [g ai/ha] +Sequestrene 330 Testplants 180 90 180 90 1000 g/ha Soybean 35 10 15 10 Amaranthus 60 60 7060 Chenopodium 30 20 20 20

Table B8: Postemergence herbicidal action of compound No. 6.1 by itselfand in combination with in each case 1000 g/ha of Seauestrene 330; rateof application 15 g, 30 g and 60 g of active substance/ha.

Cmpd No. 6.1 Cmpd No. 6.1 [g ai/ha] [g ai/ha] +Sequestrene 330 Testplants 60 30 15 60 30 15 1000 g/ha Soybean 60 55 45 45 40 35 Amaranthus60 60 60 80 70 60 Chenopodium 95 90 90 90 80 80

The increased selectivity of compound No. 2.6 (Harmony®) in combinationwith Sequestrene 330, shown in Table B5, is particularly surprisingbecause the cited active ingredient does not act as a herbicide insoybean. This indicates an increase in the selectivity of herbicidalacetolactate synthase inhibitors (ALS inhibitors) in cultivated plantsin the presence of water-soluble iron compounds.

The same results are obtained by formulating the compounds of formulaeA, C, C₁, D and B according to the Examples F1, F2 and F4 to F8.

What is claimed is:
 1. A selective herbicidal composition, comprising,in addition to customary inert formulation assistants, a mixture of a) aherbicide selected from the group consisting of sulfonyl ureas, and b)safening amount of a water-soluble iron compound.
 2. A compositionaccording to claim 1, wherein a) the herbicide of the sulfonyl ureagroup corresponds to formula A

wherein E is a group of formula

W is a group of formula

R and R₁ are each independently of the other hydrogen, methyl ormethoxy; R₂ is chloro, nitro, —CH₂CH₂CF₃, —OCH₂CH₂OCH₃, —OCH₂CH₂Cl,—COO—C₁alkyl, —COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl; R₄ is —COOCH₃, —CF₃, —OCHF₂,—OCH₂CF₃, —OCH₂CHClF, —CON(CH₃)₂ or —SO2C₂H₅; R₀₄ is hydrogen or —CF₃;R₅ is —COO—C₁alkyl or —COO—C₂alkyl or the group of formula

R₆ is hydrogen or chloro; R₇ is methyl or the group of formula

R₈ is chloro or —SO₂C₂H₅; X₁ is chloro, methyl, methoxy or —OCHF₂; Y₁ ismethyl, methoxy or —OCHF₂; X₂ is methyl, methoxy, ethoxy, —CF₃ or—N(CH₃)₂; and Y₂ is —CF₃, methoxy, —OCH₂CF₃ or —NHCH₃, and the salts ofthose compounds; b) the water-soluble iron compound corresponds toformula B  [Fe^(II,III)-Z]  (B), wherein Fe^(II,III) is the element ironhaving the oxidation number +2 (II) or +3 (III); and Z is a mono- orpolyvalent anion of inorganic or organic acids H-Z.
 3. A compositionaording to claim 2, wherein, in the compounds of formula A, E is a groupof formula

W is a group of formula

R and R₁ are each independently of the other hydrogen or methyl; R₂ ischloro, nitro, —CH₂CH₂CF₃, —OCH₂CH₂OCH₃, —OCH₂CH₂Cl, —COO—C₁alkyl,—COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl; R₄ is —CF₃, —OCHF₂, —OCH₂CF₃,—OCH₂CHClF, —CON(CH₃)₂ or —SO₂C₂H₅; R₅ is —COO—C₁alkyl or —COO—C₂alkylor the group of formula

R₆ is hydrogen or chloro; R₇ is methyl or the group of formula

X₁ is chloro, methyl, methoxy or —OCHF₂; Y₁ is methyl, methoxy or—OCHF₂; X₂ is methyl, methoxy, ethoxy or —N(CH₃)₂; and Y₂ is —CF₃,methoxy, —OCH₂CF₃ or —NHCH₃, and the salts of those compounds.
 4. Acomposition according to claim 3, wherein R₂ is —COO—C₁alkyl,—COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl; X₁ is chloro or methyl; Y₁ is methylor methoxy; X₂ is methyl; and Y₂ is methoxy.
 5. A composition accordingto claim 2, wherein, in the compounds of formula A, substituent E is agroup of formula

substituent W is a group of formula

R is hydrogen; and R₁, R₂, R₃, X₁, X₂, Y₁ and Y₂ are as defined in claim2.
 6. A composition according to claim 5, wherein E is a group offormula

W is a group of formula

and X₁ and Y₁ are methyl.
 7. A composition according to claim 2,comprising a compound of formula A, wherein E is a group of formula

W is a group of formula

R₂ is —COO—C₁alkyl, —COO—C₂alkyl or

R₃ is —COO—C₁alkyl or —COO—C₂alkyl; X₁ is chloro or methyl; Y₁ is methylor methoxy; X₂ is methyl; and Y₂ is methoxy; and a compound of formulaB, wherein Z is an anion of EDTA, EDDHA, DTPA or HEDTA.
 8. A compositionaccording to claim 7, wherein, in the compound of formula A, substituentE is a group of formula

substituent W is a group of formula

and X₁ and Y₁ are methyl.
 9. A composition according to claim 3,wherein, in the compound of formula A, substituent E is a group offormula

substituent W is a group of formula

and X₁ and Y₁ are methyl.
 10. A composition according to claim 9,wherein R and R₁ are hydrogen.
 11. A composition according to claim 1,comprising further adjuvants such as stabilisers, antifoams, viscosityregulators, binders, tackifiers or other active ingredients as well asmetal chelates and further trace elements.